Electrical transmission of graphic messages.



G. SELLERS. ELECTRICAL TRANSMISSION OF GRAPHIC MESSAGES.

APPLICATION FILED JULY 18, 1908.

Patented Nov. 9, 1909.

8 SHEETS-SHEET 1.

FIG. 3

[FRom gecnveg Witnesses:

Inventor 6172? r? SeZZenr,

G. SELLERS.

ELEGTRICAL TRANSMISSION OF GRAPHIC MESSAGES.

APPLIOATION FILED JULY 1a, 1908.

939,338, v Patented Nov. 9, 1909.

3 SHEETS-SHEBT 2.

FIG. 4

Inventor Witnesses:

G. SELLERS.

ELECTRICAL TRANSMISSION OF GRAPHIC MESsAGEs.

APPLIOATION FILED JULY 18, 1908.

939,338. Patented, Nov. 9, 1909.

8 SHEETS-SHEET 3.

Inventor Witngsses: 0

W I Glber? ,SeZZmr. a /2 [2E [UL 16711 By J 475% MW A [form ('ys.

tional Encyclopedia, Bell,

UNITED STATES PAEENT OFFICE.

GILBERT SELLERS, OF CHICAGO, ILLINOIS.

ELECTRICAL TRANSMISSION OF GRAPHIC MESSAGES.

Specification of Letters Patent.

Patented Nov. 9, 1909.

Application filed July 18, 1908. Serial N0. 444,227.

ings, forms a full, clear, and exact specification, which will enableothers skilled in the art to which it appertains to make and use thesame.

his invention has general reference to, and its object is the,improvements in the electrical transmission of graphic messages,pictures, photos, prints, &c., and vislble views of fixed, living, andmoving objects, and to reproduce the same at the receiving stationeither as a graphic message or as a visible, stationary or movablepicture; and it consists, essentially, in the novel and peculiarcombination of parts and details of construction as hereinafter firstfully set -forth and described and then pointed out in the claims.

This invention has its basis upon a series of physical and electricalphenomena and facts the application of which, and the manner in which,they are carried into effect, may be briefly stated, as follows:According to Plateau the persistence of impression on the retina is inordinary light one half second, such persistence depending on theintensity of the light; Newton observed a spot on the retina or daysafter looking at the .sun. This is the cause of the streak across theretina due to a rapidly moving object. (See Plateaus investigations inGanots Physics by Ganot and Atkinson.) Again according to Sale, Siemens,Internm Girard, and others, there are substances-which, when interposedinto the electric circuit and exposed to various grades of light, arealmost instantaneous in their resistance of the circuit or in loweringand raising the resist-,

ance relative to the light they are bathed in. In the photophone and thespeaking arc the wonderful control of electrical resistance ispractically proved through the light cast u on crystallized selenium oron a lamp b ack joint. rapid changes to take place in the resistanceSuch substances cause suchofthe current as to reproduce the human voiceranging from 1,000 semi-vibrations to 40,000. g. '0. Von Hulmholt7sestimations in one second. This means as high and even higher than20,000 changes may take place in the electrical resistance of acrystallized selenium or lamp black joint in oneahalf second. Then if aselenium point is passed through a field of light containing 20,000 compete changes and finish its flight in onehalf second, 10,000 electricalvibrations will be produced in that time -.in the circuit. Again, if apencil of light pass before the retina over a field corresponding to thefield over which the selenium point was passed and durin thesame time,one will see that entire fiel at the latter instant of the li htspassage. Then if the intensity of that fight 1s so regulated by those10,000 electrlcal vibrations, the illuminated field before .the eye willduplicate the field over which the selenium point was passed. These arethe steps that enable me to reproduce such a scene instantaneously andso quickly that a series of scenes may be made to follow in such a shortsuccession that the sensation of movement is the result. In order tocarry these principles into efiect and attain the results I constructthese instruments substantially as shown in the accompanying sheets ofdrawings, which serve to fully illustrate this invention, and in which-Figure 1 is a longitudinah'vertical section 1, in Fig. 1, is the sendingcase or receptacle having a bottom 2,.sides 3, and ends 4:.

In the bottom 2 there is a transverse-slot 5, for the exit of a film 6.Adjacent to one of the ends 4, of the case 1, is journaled, upon a shaft7, a film containing roller or spool 8,

which roller is provided with a brake band 9, to apply friction tosaidspool and thereby prevent undue unrolling of the film 6. In aboutthe center of the case 1 and at the same height .asshaft 7 .is journaleda second is to provide a speed-governing shaft 10, upon which is mounteda filmdeflwting roll 11, from which roller the film 6 deflects downwardand passes out of the case 1 through the slot 5. Directly above roller11 is a feed-roller l3, impin ing upon the film passing between said rolers 11 and 13. Roller 13 is fastened to a shaft 12, one end of whichprojects through one of the side walls 3 of the case 1, and has at itsextremity a miter-gear 14; meshing with this is a similar gear 15,aflixed to an upright shaft 16, wluch shaft is journaled in a bracket17, fastened to the extended top 24, said extended top also serving toincase feed-roll 13. At the upper end of shaft 16 is a worm-gear 18,meshing with wormscrew 19 on shaft 20, of a motor 21, said motor beingsupported on the depressed top 22 of the case 1, and is energized fromvoltaic cells or other source of electric current 23.

Motor shaft 20 extends beyond worm-screw 19, and near its outerextremity revolves in a bearing in a bracket 25, resting on the curvedtop 39 of the case 1. On this bracket, and encircling shaft 20 is acylindrical shell 26, within which are located and revolve brake-shoes27. These shoes are connected by links 28, through a slot 32, in theshaft 20, to a sliding spindle 29 in the center of said shaft. Thisspindle 29 terminates in a head 38, to which are connected the shanks 30of two governor balls 40; the said shanks being pivoted at 31 to the endof the shaft 20. Within the shaft 20, and bearing against the spindle 29is a spiral spring 33, and against this spring, butts a pin 34.

Upon the shaft 20 is a screw thread 37, overwhich fits a threaded collar36. Against this collar is placed a key 41 passing through a slot 35 inthe shaft 20, which key pushes against the pin 34.

The office of the mechanism just described device for the motor forpurposes hereina er to be described. Its operation is as follows: As themotor-speeds up the governor balls 40 are carried outwardly bycentrifugal force, and push the spindle 29 inwardly, causing the links28 to straighten out and the shoes 27 to finally impinge against theinner surface of the stationary shell 26. The friction so enerated willretard the motor speed until lthas fallen off sufliciently to allow thegovernor balls to drop and withdraw the shoes 27 .from'contact withthe-shell. To adjust the governor for various speeds, the collar 36 maybe screwed toward or away from the slot 35, and thereby, through theintermedium of the key 41 and pm 34, create greater or lesser pressureupon the spring 33, which, in turn will establish greater or lesser.resistance to movement of the spindle 29.

Mounted upon the shaft 20, at a point central, approximately, betweenthe film rollers 8 and 11 within the case 1, is a disk 42. This diskconsists of a hub 43, and two sideplates 44, s aced a proper distanceapart b said hub. ear the periphery of this dis 42, and between theside-walls 44 are formed a series of equally-spaced radial cylindricalpockets 45. At the center end of these pockets, and flush with theperiphery of the disk are placed condenser-lenses 48, which are soground as to convert parallel rays of light into divergent rays withinthe pocket. The bottoms of these pockets 45 are closed by cups of fiber,rubber, or other insulating material 47. Within these cups are fixedcircular cells of selenium 46. From these selenium cells lead wires 50which are connected to one of the lates 44. Wires 49 also lead from these enium, but they are thoroughly insulated from the plates 44, and areconnected to commutator-sectors 51 as described below. Adjacent to thedisk 42, on the shaft 20, is located a commutator 52 which is insulatedfrom the shaft by the insulation 53. Upon the periphery of thiscommutator are a series of metallic sectors 51, radially arranged andinsulated from each other, and corresponding in number to the number ofpockets -45 within the disk 42. To each one of these sectors isconnected a wire 49, mentioned above, from that one of the seleniumcells located opposite Each particular sector, as clearly shown in Tothe shaft-supporting bracket 25, already described, is attached acommutatorbrush stud 55, but thoroughly insulated therefrom byinsulation 57. At one end of this stud is attached a binding post 56, towhich is led the current-transmlssion wire 60 from the receivinginstrument, and at the other end is a' commutator-brush 54, with itsfree end in contact with one of the commutator sectors 51. To thebracket 25 is fastened a binding-post 58, from which is led thecurrent-transmission line 59 to the receiving instrument. Attention isnow called to the fact that when the commutator is revolved, and thebrush 54 is passing over the insulating bridge between adjacent sectors51, the brush is in contact with both adjacent sectors for a very shortperiod of time or space.

The top 39 of the case 1, below the disk 42 is of convex contour, itscurvature being concentric to the periphery of said disk, as clearlyshown in Fig. 2. Directly below the center of the disk 42, and throughthe top 39 is located avery narrow slot 61. The length of this slot isequal to the angle formed between the centers of two adjacent pockets 45in the disk 42, as seen in Fi 2. The relationship of the slot and thepoo rets is such that when the disk 42 is revolved, and one of thepockets is passing beyond the range of theslot, the next adjacent pocketis just entering into ran e.- In a similar manner, the relationshippockets and commutator sectors is such that when one pocket is leavintherange of the slot 61, the com- ;mutator-rush is "passing from thecommutator-sector belonging to that pocket, tothe sector belon-gln tothe pocket jaist enteringintorange 0 said slot. 1

By reference to Fig. 1 it will be observed m that the film 6, alreadyreferred to, in

range of the slot 61.

and on either side of the reflector 641- are two a'plane directly belowthe top- 39', and directl y helow said filmina perpendicular line withthe slot 61, is an electric lamp 63 curved rollers, 62 to curvethesurface of the film- 6=to the curvature of the" top 39 as the film ispassing across the slot 61. Current for the lamp- 63 isprovidedby thecells.- or other source of current 65. I

Referring to the gears 14, 1:5, 18, and

,worm-screw 19, which compose the filmfeeding mechanism, it will now beunderstood that the ratio of this gearing is such that the film is fedacross the slot 61 as many times the width of the slot 61', as

there are pockets inthe' disk- 42, one revolution of the disk; that isto say,- if there are eight pockets in the disk the fil m must moveforward eight times the width ofthe slot during one revolution of thesaid disk. Every time a pocket with its selenium cell has traversed therange: of the slot, the film has moved forward thewidth of the slot.-

The operation of this sender may now be described as follows: Assuming alive electric circuit to be established by the wires 59 and -60, thegoverning mechanism is adjusted to the: proper speed, the lamp 63 turnedon and motor 21 started. The electrical conductivity of selenium issusceptible to the action of light. Its electrical resistance issusceptible instantaneously to an in finitude of changes by saidlight-action.

The passing of the film 6 .before' the slot 61,

- with the light projected through said film with its changes in light,and shadow, and contrasts, will afiect the conductivity of the seleniumwithin the pockets as the disk revolves rapidly before" the slot, andthere will be set up in the continuous current flowing through thetransmission-circuit an infinitude of variations in theintensitythereof, equaling exactly the infinitude of changes in thelights, shadows and contrasts of ,the' image onthe film.

The foregoing description has reference entirely to the transmlssion ofan image upon a; film. If, however, it is desired totransmit an imagedirect from life or nature,-

the' sender illustrated in Fig. 4 is employed. The governing mechanism,the disk, pockets, selenium cells, and motor are precisely the same asin the first instance, but directly in front of the disk 42, Fig. 4:, islocated a ground glam 66,- the sole purpose of which is to per mm thefunctions of arange-finder; In front of this glass is a dark slide 67,having a narrow slot 85, located on a center line with the disk 42 andof a length equaii to the angle formed between the centers of adjacentpockets 45 in the disks 42. The length of this slot determines the widthof the Image projected: on Y the ground-glass range finder.

\ To a frame 86,-su-rrounding the dark slide 67 and ground glass 66-, isattached a flexible camera bellows 68, terminating in a camera front 69,in which is afliared a proper photographic lens 70.- This front 69 issusceptible oi a perpendicular movement equal to the height of the imageprojected on the ground glass and isidedin its motion by the uprightguides These guides are stiffened at their upper ends by a brace 72 andat the bottom by the support 73.

Tothe edges of the camera front 69 are pivoted rods 74;, which connectsaid front with vibratin levers 75, which: levers are journaledat t ei ropposite ends on brackets 81. On said levers 75 are rollers 80engaging'racewa cams 79; These cams are fixed to a shaft 7, which isjournaled in brackets 76. Upon this shaft is keyed a worm gear 78-,which meshes into worm-screw 19' on motor shaft 20'. The raceway cams 79re volve in the direction of the arrow shown thereon, and in theposition shown in Fig. 4!, it will be observed that only a very slightmovement is necessary to permit the rollers 80"to drop down thepractical radial slots- 8'6, returning the levers 75, connecting rods74, lens 70, camera front 69, and bellows 68 tothe positions shown indotted lines in- Fig'. 4. To nullify the shockdue to the sudden drop ofthese arts spring bumpers are placed under the: rec ends of lovers 75.

These bumpers consist of external cylin drical shells 82 telescopingover smaller shells 83. Within the latter are spiral springs 84, whichare in a normally extended? condition. When thepaa-ts above mentioned:drop, the ends of the levers 75. strike shells 82 and compress springs84, thereby deadening the jar that would otherwise occur;

The speed of the upward movement of the lens and its adjacent parts isequal to the width of the slot for every pocket 45 in the disk 42 thattraverses the slot 85 in the dark slide 67. Thus if there" are eightpockets around the disk 42, then the lens moves upward eight widths ofthe slot for each revolution of the disk.- This upward movement is at a:constant speed, due to the raceway in:

vment is about as 1:250.

The transmission of moving images produced by the progress of a race, apugihstic encounter, or any other life motion, is accomplished bykeeping this sending apparatus in continuous motion, and as the lenscompletes about 250 cycles per minute, the motion in life will becorrectly transformed into an infinitude of current variations in thetransmission circuit, through the intermedium of the selenium cells.

In Fig. 5 is illustrated the receiving mechanism, which consists of acase or receptacle 87 having a bottom 88, sides 89, top 90, and a bridge91 for su porting the operatin mechanism. Upon this bridge near one enof the case is mounted a motor92, operated by a current from a source ofelectricity 93.

The shaft 95 of this motor has at one end a' the far end of the case 87and isjournaled in a bracket 115. On said shaft, adjacent to thisbracket is keyed a spider 113, having a plurality of equa ly spacedradial arms 117, each terminating in hinge-lugs 118. To these lugs, arehinged, by means of hinge ears 114 and pintles 119, Fig. 9, a pluralityof mirrors 112. The opposite ends of these mirrors are connected by lugs116 and links 111 to a sliding collar 110, which is adapted to freelyslide to and fro on shaft 95. The number of mirrors 112 hin ed to thespider 113 corresponds to the num er of pockets 45 in the sending disk42; also the circle described by the revolution of the mirrors' is ofthe same diameter as that of the said sending disk. Furthermore, thegovernor 94 is set to the same speed as the governor on the sendingmechanism, and the size of each mirror is the same as the field of theimage projected upon the oun'd-glass range finder 66 of the said sendingapparatus.

Upon the periphery of the already mentioned sliding co lar 110, isturned a groove 109 for the reception of the forked end 108 ofavibrating lever 105. The opposite end of this lever is ivoted to abracket 107, and intermediate 0 its length, is journaled a roller 106,which fits in spiral groove 120 of a raceway cam 104. Said raceway cam-'roller 106 passin t .radial eaaeee is keyed to a shaft 102, which issuitably journaled in bearings not shown. This shaft also carries a spurgear 103, the latter meshing with intermediate gear 100, which revolvesfreely on a stud 101, and this in turn, meshes into worm gear 97, andthe last named derives motion from the worm screw 96 on the motor shaft95. Said worm car 97' revolves freely on stud 98 support in bracket 99.

Upon revolving cam 104, it will be observed, that through the action ofvibrating lever 105, sliding collar 110, and links 111 the near ends ofmirrors 112 will be forced radially. outward until said cam 104 has madeone revolution when, because of the hrough the ractically ortion of t e,oove 120,t e mirrors are su denly returne to their original position.These complete 0 cles are accomplished at the same spec and follow eachother with the same ra idity as the cycles of the lens 70, Fig. 4. otherwords, the motor 92 is synchronized with the motor 21, Figs. 1 and 4,and necessarily the movement of the mirrors is in synchronism with themovement of the said lens 70, or with the movement of the film 6, Fig.1.

Centrally above the top-most mirror 112 and of a size suflicient topermit rays of light 121 to be spread over the surface of said mirror,is cut an opening 122 in the top 90 of the case 87. Light-rays emanatefrom a light 123 of great intensity, which light is operated by acurrent from an electrical source 124. Surrounding this light is aparabolic reflector 125 and in front of the same a condensing lens 126,which focuses the rays 121 upon a small mirror 127. From there the raysare projected through a proper lens 128 and spread over the surface ofmirrors 112. Adjoining the lens 128 is an absolutely opaque screen 129for purposes hereinafter described.

The small mirror 127 is suspended by a fine quartz fiberwire or thread130 in a high frequency disk galvanometer 131. Below this mirror is susended a small silver disk 132 within a coil 133 consistin of acomparatively few turns of insulate wire. This coil, through its bindingposts 134 and 135, forms part of the transmission circuit which iscomposed of the wires 59 and 60, the voltaic cells 136, the saidgalvanometer 131 and the sending apparatus. Now, the diskgalvanometer131 has the pro erty of causin the disk 132 to oscillate a out the axis0 the fiber thread 130, whenever a current, no matter how feeble ispassed through the circuit. The are of the oscillation and the rapidityof successive oscillations depends entire of the variations in theintensity of the cury upon the variations and the rapidity 1 rentpassing through the circuit. Therefore,

' ceases as created by the selenium cells in the send ing apparatuswillreduce an infinitude of oscillations of the isk 132, the arc of eachoscillation representing the light value of that particular portion ofthe sending image which caused it. And the rapidity of these successiveoscillations, will in the same manner correctly represent the lightvalue of the successive portlons of the image as picked up by theselenium cells. The mirror 127 being also attached to the quartz fiber130 which suspends the disk 132, will naturally oscillate with the disk.

In order to understand the process of reproducing the image in thereceiver, attention is called to Figs. 6 7 and 5. Assume the light 123to be turned on, the motor 92 in operation, and an open circuit in thetransmission line. Or, assume the lens 70 of the sender to be capped. Inthis case the disk 132 of the galvanometer will be in a normal position,and that position is shown in Fig. 6, wherein all the light rays fromlamp 123 are blanketed upon dark screen 129 and none of them passthrough the lens 128 to the mir rors 112. If the sender now be startedand a current established in the transmission line, the disk 132 andmirror 127 will oscillate and permit a portion of the light rays 121topass through the lens 128 and be deflected upon the mirror 112, theamount of light so passing through the lens being directly proportionateto the light value of that particular portion of the sending image atthat precise instant. As the light value of the image increases, thecurrent in theline increases, and the mirror 127 twists through agreater are, permitting a greater portion of light to pass through thelens 128 and upon the mirrors.

112. When the mirror 127 has twisted sufficiently to ermit the fulllight from the lamp 123 to e spread upon mirrors 112, the equivalent ofsunlight streaming through the lens 70 of the sending apparatus has beenther observed that the image of the message,

obtained. The relative position of the mirror 127 to the mirrors 112 issuch that the radial movement of the mirrors 112 from the normal to theextreme position shown in dotted lines in Fig. 5, will cause the rays121 to travel from the point A on said mirrors to point B thereon. Thismovementocorresponds to the movement of the lens 70, and as therevolution of these mirrors is synchronized to the revolution of thesending disk 42, the exact conditions existing in the sending apparatusare reproduced in the receiver. The li ht values projected upon themirrors 112 being relatively the-same as in thesending image, theimpression produced upon the human eye upon lookin through the opening122 of the receiver w1ll be that of the image transmitted. It will befuror that of a moving object, a view, &c., received at the receivingstation is exhibited to the human eyejlgreuhgh the opening 122 upon themirrors 112 w ieli arpassing' be; fore the retina of the eye in rapi'succession and overlap each other seas to appear to the eye as a movingpicture if the orlginalwa a moving picture, or as a stationary or fixeobject, as the case may be. To throw these pictures upon a screen orupon a sensitive film, they arepicked up by a projectlon apparatus (notshown) ofusua construction from the mirrors 112 and then developed inthe usual manner. 1

In the foregoing specification I have described the preferred form andconstruction and instrumentalities with which my present invention iscarried into eflt'ect, but I desire it to be distinctly understood thatthe various details of the several instruments described may be variedin many ways without departing from my invention. Having thus fullydescribed this invention I claim as new and desire to secure to me byLettersPatent of the United States- 1. Means for electricallytransmitting graphic messages and views of objects, including amessage-sheet of varying degree of transparency; a source of 1i ht;means for projecting the light from sa1d source of 2. The method ofelectrically transmit-' ting messages and views ofobjects, whichconslsts in exposing sald messages, and

views of objects, successively and step by step to a series of rapidlyrevolving light-sensitive substances which will change its electric con:

ductivity in accordance with the intensity of the lightacting upon saidsubstances, and transmitting the electrical undulations or variations inthe intensity of the current and the rapidity of the undulations to areprodu'cin instrument and to translate these electrical undulations andvarying impulses into light-rays of correspondingly varying.

intensity and projecting the same upon a' reflecting surface whichrenders them visible to the human eye; j,

3. In an apparatus for electrically transmitting messages, pictures andimages 0 objects, means for translating said image into a series ofelectrical im ulses'; a transmission circuit; and means or retranslatingthese electrical impulses into a duplicate of the sendin image,including a series of revolving re eeting surfaces. e

4. In an apparatus for electrically transmitting messages, pictures andimages of objects, means for translating said image into a series ofelectrical impulses of varying intensity; a transmission-circuit, andmeans for retransla ting these electrical impulses into a duplicate ofthe sending image including a series of revolving reflecting surfaces.

5. In an apparatus for electrically transmitting messages, pictures andimages of objects, means for translating said image into a series ofelectrical impulses of varying rapidity; an electrical transmissioncircult, and means for retranslating said electrical impulses into aduplicate of the original image including a series of revolvingreflecting surfaces.

6. Means for translating lights and shades of an image into electricimpulses correlated to each other as the lights and shades of the imageare correlated, a transmission circuit, means for translating saidimpulses into correlated light-rays at the receiving station,

7 and further means for projecting said rays upon a reflecting surfaceto render the same visible, said reflecting surface including a seriesof revolving mirrors.

7 Means for translating the optical variations of'an image into anundulating current, 'said undulations correlated to each other as saidoptical variations are correlated, means for transmitting ,saidundulations, and further means for retranslating said undulations into aduplicate of the optical variations of the sending image, said meansincluding, a galvanometer and a series of revolving mirrors.

8. In an apparatus for electrically transmitting graphic messages,pictures and images of objects, a transmitting instrument, including atransparent or translucent message-sheet; a source of light; a motor; adisk; a series ofcells in said disk; an element in said cells capable ofbeing electrically excited by rays of light; an electric circuitv ofwhich the electrically excitable element forms a part; means foroperating said motor; and means for moving the message-strip between thesource of light and the cells, said cells and the means for moving themessa e-sheet being revolved by said motor at pre etermined speed.

9. In an apparatus for electrically transmitting graphic messages,pictures and images of objects, a transmitting instrument, including asuitable message-sheet; a source of light; a motor; a circular disk; aseries of cells in said disk; a selenium-element in each of said cellsand insulated therefrom; a motor-operating means; means for moving themessage-sheet between the source 0 light and the selenium-elements; acommu- 'tator consisting of a series of sections each said source oflight 11 on the revolving disk.

and its cells, and an e ectric circuit of which said element is a part.

11. In an apparatus for electrically transmitting messages, pictures,and images of objects, means for projectin said message, picture andimage successive y and step-bystep upon a revolving disk having a senseof cel s each of which contains an element which is electricallyafi'ected by the light and shade of said message to increase anddecrease its electric conductivity in accord with the lighter and darkerportions of said image, and an electric circuit of which said clementforms a part.

12. In an apparatus for electrical transmission of graphic messages,pictures and images of objects, a transmitting instrument including atransparent or translucent message-strip; a light-secure chamber; aslotted aperture in said chamber, a source of light below, and in-lineof, said aperture; a series of revolving cells located above saidaperture; a motorfmeans for governing the speed of said motor, anelectric circuit of which said revolving cells are a part, and means formoving the message-strip below said slotted aperture and above thesource of light. i

13. In an apparatus for electrically transmitting messa es, pictures andimages of objects, a son ing instrument, including a light-tight case; asource of light in said case; a reflector surrounding said source oflight, there being a slotted aperture in said case through which therays of light are projected; a transparent or translucent message-sheetcontaining a picture of the matter to be transmitted; means for movingsaid message-sheet between said source of li ht and the slottedaperture; a revolving isk having a series of cells; seleniumelements insaid cells and insulated therefrom but electrically connected with saiddisk; a motor; a source of electrical energy to operate said motor;means for revolving said disk and moving said message-sheet atpredetermined speeds; a governor for regulating the speed of said motor,a commutator, the several sections of which are elec- V the raystrically connected with each of said selenium elements, and an electriccircuit of which said disk and its selenium elements are a art.

ratus as described, a rotatable disk; a series of cells in said disk; acommutator, the sections of which correspond in number with that of thecells in the disk, and a speedgovernor having means for regulating and schronizing the number of revolutions 1n tii: transmitting and receivinginstruments.

15. In a transmitting apparatus as described, a rotatable disk; a seriesof cellsin said disk, a commutator having a series of sectionscorresponding with the number of cells in said disk and in electricalconnection therewith; a motor for revolving said disk; a overnor for reulating the speed of saiddis a series of eed-rolls; a suitablemessage-sheet; and means for moving said message-sheet at a unison withthe revo utions of said disk.

16. In an apparatus of the kind described, the combination, with atransmitting instrument which translates a picture, and view of objects,into a series of electrical impulses of varying rapidity, and intensity,of a transmission circuit for said impulses; a receiving instrumentincluding a source of light, a alvanometer; means for directin roin saidsource of light upon sai galvanometer and means for directing the raysof light from said galvanometer to a reflecting surface consistlng of aseries of revolving mirrors, whereby the electrical impulses received atthe receiving instruments are retranslated into a visible image of thematter sent by the sending apparatus.

17. In an apparatus of the ind described, the combination, with a sendininstrument which translates a message whic consists of a graphic orvisible picture or image into a series of electrical impulses of varyingrapidity and intensity, 0 a transmission circu t'for said electricalimpulses; a receiving instrument including means for converting theseelectrical impulses into rays of light 14. n a transmitting andreceiving apparedetermined s eed in 0f varyng intensity; a series ofreflecting surfaces; means for projecting these rays of light upon saidreflecting surfaces, the angularity of which may be varied to correspondwith the variations of the electric current received at the receivingstation.

18. In an apparatus of the kind described, the combination, with atransmitting instrument which translates a message consisting of agraphic picture, and a view of objects, into a series of electricalimpulses of varying rapidity and intensity, of a transmission circuitfor said electrical impulses; a receiving instrument including agalvanometer acted u on by said electrical impulses, a source of ight;means for projecting the rays of light rom said source of light upon thereflecting mirror of said galvanometer; a reflecting surface consistinof a series of mirrors mountedupon an ax e, a motor for revolving saidmirror, and means for changing' the angularity of said mirrors, wherebythe varying electrical impulses acting u on the galvanometer translatethese impu ses into a visible picture of the message sent by thetransmitting instrument.

19. In a receiving instrument for electrical impulses varying inintensity and rapidity, means for translating these varying impulsesinto rays of light of varying intensity, and an instrument for renderingthese rays of li ht visible, said means including a suitab e case; anelectric motor in said caser a reflector consisting of a series GILBERTSELLERS. Attest:

WILLIAM O. STARK, MICHAEL J. STARK.

